This invention relates to an improvement in process for chemically inducing the production of oleoresinous material in association with living wood cells, typically in a living pine tree from the U.S. southeast such as slash pine or loblolly pine, and to oleoresin-enriched wood harvested from such tree.
Oleoresinous material can be recovered from such oleoresin-enriched wood by conventional pulping or extraction methods. "Naval stores" such as turpentine and rosin are significant components of the recoverable oleoresinous material.
The prior art most relevant to this improvement is believed to be U.S. Pat. No. 3,839,823 assigned to the United States of America as represented by the Secretary of Agriculture; the Komissarov et al article appearing in the U.S.S.R. journal "Gidroldz. Lesekhin. Prom." 1968, 21 (5), 21, and abstracted in Chem. Abs. 1968, Vol. 69, 88119; The Study Plan and Final Office Report of T. A. Harrington to the Naval Stores and Timber Production Laboratory of the U.S. Forest Service, Olustee, Florida, FS-SE-1501, Study NS 146, September 1967, entitled "A Preliminary Evaluation of New Chemicals as Gum Flow Stimulators"; The Study Plan of D. A. Roberts to the Naval Stores and Timber Production Laboratory of the U.S. Forest Service, Olustee, Florida, FS-SE-1501, Study NS 165, May 1969, entitled "Extent of Cell Kill in Slash and Longleaf Pines Following Treatment with 2,4D-, Sulfuric Acid, and Paraquat"; Research Note SE 191 dated April 1973 from the U.S. Forest Service at Olustee, Florida; "Proceedings of the Annual Meeting of the Lightwood Research Coordinating Council," January 22-23, 1975, Jacksonville, Florida, published March 1975, and available from William Hogan, Chevron Chemical Company, P.O. Box 160, Ocoee, Florida 32761; and Ranua, Pap. Puu 1975, 57(9) 597-9, Helsinki, Finland.
The most pertinent parts of these references have to do with applying dilute, sublethal aqueous solutions of normally herbicidal bipyridylium salts to living pine wood xylem. This in a relatively short time (eg. 3-6 months in the U.S. south) induces the formation of "lightwood" (also known as "litewood"), ie. wood with a heavy concentration of oleoresins even to the point of being translucent in thin section. Such phenomenon is referred to as "lightering".
Commercially available bipyridylium salts include the herbicides paraquat and diquat which are known also by the trademarks Gramaxone and Reglone, respectively. Such marks are the property of Imperial Chemical Industries, Limited. The foregoing art and other reference material of a collateral nature are cited in the patentability brief accompanying this application; all of it is expressly made a part of this application.
Advantages of the present improvement over the closest prior suggestions include the fact that the distribution of increased oleoresinous material induced in the tree is far more even when using this improvement than when using a bipyridylium salt solution. In the latter instance the first bolt (that is, the first 5 feet of trunk above the zone of treatment) is quite rich in oleoresin after a reasonable period of time (eg., three months or more), and this effect attenuates with altitude in the trunk. In contrast, the comparative evenness of such distribution from use of the present improvement provides wood for a paper pulp mill that will process well. The improved treatment also is believed to be less of a shock to or stress on the tree, yet overall in the tree there is an increase in yield of deposited oleoresinous material that is substantially equal to that observed in comparable trees subjected to the bipyridylium salt treatment.
Other advantages include the clearly lower cost of the preferred instant treating chemicals. Additional advantages will be evident from this specification. Thus, while the present active agents are not commercial herbicides, they, as amines, usually stink a bit; in concentrated form some of them can be somewhat irritating to human skin. However, they are not to be classified as poisons as are the herbicidal bipyridylium salts. In fact, many of the instant active substances are considered quite biodegradable; weak solutions of same can be considered nitrogenous fertilizer.